Dec. 12 (Bloomberg) -- Major League Baseball will discover tomorrow what a former U.S. senator and federal prosecutor found out about drug use in the sport.

Former Senator George Mitchell will hold a 2 p.m. press conference in New York to announce results of his probe, according to a statement released by his law firm, DLA Piper LLP. Baseball will hold a separate press conference at 4:30 p.m.

According to reports in the New York Times and other media, at least 50 current and former players will be identified as cheating with steroids, stimulants and human growth hormone.

The Associated Press said Most Valuable Players and All- Stars will be named and that Mitchell will show ``deep problems'' in a drug culture that plagues the sport, citing two people with knowledge of the findings it didn't identify. The news agency added that Mitchell won't discuss amphetamines and will call for baseball's drug testing to be strengthened and conducted by an outside agency.

The report will be about 300 pages plus attachments, and will be ``sharply critical'' of both baseball and the players' union ``for tolerating the use of performance-enhancing drugs over an extended time,'' the Times said today on its Web site. It quoted an unidentified person familiar with the investigation.

Mitchell's Evidence

Baseball officials reviewed the report compiled by Mitchell as part of a 20-month investigation into the use of performance- enhancing drugs in the sport and found it ``harsh,'' the Times said earlier today, citing a person familiar with the document that it didn't identify.

The newspaper, citing a different unidentified person, said the Major League Baseball Players Association was ``upset'' at the portions of the report of which it was aware.

Mitchell may have based the report on documentary evidence, including canceled checks, telephone records and shipping slips, rather than positive drug tests, the Times said.

The New York Daily News reported yesterday on its Web site that the report may contain the names of 60 to 80 former and current players and is largely based on information from former New York Mets clubhouse worker Kirk Radomski, who previously pleaded guilty to distributing steroids.

Pat Courtney, a Major League Baseball spokesman, declined to comment on the Daily News report, while MLB President Bob DuPuy didn't immediately respond to an e-mail seeking comment. Players Association spokesman Greg Bouris didn't immediately respond to a voice-mail message left at his office after regular business hours.

48-Hour Review

Baseball officials arrived at Mitchell's office yesterday and began a 48-hour review period, the Daily News said, citing people familiar with the investigation who asked not to be identified. The league is looking over the report to ensure that no confidential information is released in violation of a collective-bargaining agreement with players.

Mitchell was tabbed by Commissioner Bud Selig in March 2006 to head the steroid investigation after reports linked the drugs to players including Barry Bonds, the sport's all-time home-run leader.

To contact the reporter on this story: Larry DiTore in New York at lditore@bloomberg.net; Dan Bollerman in New York at dbollerman@bloomberg.net

Last Updated: December 12, 2007 20:08 EST